This proposal has been developed in response to a call for studies on obesity (PA-91-99). Our specific goal is the longitudinal study of central obesity and related risk factors found to be associated with hypertension and atherosclerotic cardiovascular disease (ASCVD) in our previous cross-sectional studies of Japanese Americans (45-74 yr). Baseline measures were previously obtained and we can now prospectively test exposure-disease hypotheses in our study sample from whom we can expect excellent cooperation. The following is our, general hypothesis: ASCVD, hypertension, and/or NIDDM develop in Japanese Americans when there is a truncal pattern of weight gain (central adiposity), which is in turn accompanied by insulin resistance, hyperinsulinemia, and lipid abnormalities. This cluster of abnormalities has been called "Syndrome X". It is postulated that "Syndrome X" develops in Japanese Americans in response to environmental (behavioral) factors, many of which reflect "westernization" in this ethnic group. The research plan focuses upon the relationship between central obesity and metabolic changes and disease outcomes associated with "Syndrome X" along with the behavioral variables that we believe are potential risk factors for the development of this cluster of abnormalities. The proposed research includes both nondiabetic and diabetic subjects who are second- and third-generation Japanese-American men and women. There are five specific hypotheses that will guide this research.